UPDATE: Crews at work to repair Chelmsford sinkhole

CHELMSFORD -- Crews are at work repairing a sinkhole next to Boston Road less than a mile south of Chelmsford center, with a detour expected to last through Thursday.

Among the initial tasks are finding out what type of piping will be needed where the ground wore away next to the road, said Gary Persichetti, the town's public works director. National Grid was on site to help, he said.

"It's going slow. The weather's not good," Persichetti said Monday morning. "We're doing what we have to do."

The sinkhole is just north of Brian Road, a residential road not far north of the intersection of Boston Road and Parker Road. The sinkhole is about half a mile south of the library.

Traffic is being detoured on two paths, for northbound and southbound traffic.

Northbound traffic is being diverted to Parker and Acton roads, which is about 1.7 miles. Southbound traffic is being diverted to Warren, Turnpike and Mill roads, which is about 3.1 miles.

The detours are expected to last through Thursday.

Traffic Monday morning was moving smoothly, with police officers stationed in numerous locations along the detours, including at Turnpike and Mill roads and Boston and Mill roads.